Air New Zealand will add two more Boeing 787-9 Dreamliner to its fleet.
This will take the number of Dreamliners to 12 by the end of 2018.
Air New Zealand last week added its third 787 to its fleet.
The airline's chief executive Christopher Luxon announced the fleet investment at an event in Sydney today.
"his investment is possible as a result of our strong commercial results. As the airline's commercial performance continues to improve, we are focussed on reinvesting our profits directly back into the business on products, services and fleet to further enhance the customer experience and to ensure the business remains strong and competitive."
The aircraft - which sell for $150m to $200m - was a key component of its growth strategy.
"These new aircraft will provide us with additional flexibility as we move forward with our growth plans," said Luxon.
Earlier this year Air New Zealand became the first airline in the world to take delivery of the Boeing 787-9. The airline first operated the aircraft to Sydney followed by scheduled services to Perth, Shanghai and most recently Tokyo.
"The entry into service programme has gone very smoothly and we've been incredibly pleased with the aircraft's performance. Feedback from customers has also been very positive with many commenting on the cabin fit out, our new inflight product and entertainment system," said Luxon.
One of its 787s was hit by lightning when coming into land in Perth late last month but re-entered service four days later after checks.
The aircraft is largely made of carbon fibre and its lighter weight and more efficient engines offer up to 20 per cent fuel savings on equivalent size older planes.
The airline has another six 787-9 purchase options still available.